Dynamic modification and application of wing double-beam model

In order to investigate the characteristics of vibration load at each frame along airframe transmitted from the engine vibration though the wing structure, a new double-beam dynamical model with 28 ribs of airliner's wing is presented in this paper. According to the results of the sensitivity analysis for unidentified parameters of the original double-beam model, the effective structural design variables, such as the bending stiffness, torsion stiffness of wing beams and ribs are chosen. Through modifying structural parameters of key wing ribs, the double-beam model's dynamical characteristic has been improved, in which the maximum error in first six modal frequencies between the double-beam model and a all-size wing FEM model in Ref.[8] is lower than 11.11%. Then a half-full dynamical model with the Pylon-Wing-Airframe of airliner is built, and the vibration load at each frame along airframe transmitted from engine vibration through Mounting-Pylon-Wing is calculated based on it. The acceleration distribution along airframe at main engine feature frequencies under cruise condition is obtained. These results prove that the double-beam dynamical model is better to meet the research needs for the airframe vibration calculation and transmission path analysis of engine vibration, and provides the technical preparation for vibration reduction & isolated mounting system design of wing and pylon structures.